. >> reporter: and in south bend, indiana, wbnd finding a pen maker. and with their help, he's now selling his made in america pens to the world. >> going to china and japan instead of the other way around. >> reporter: and it turns out this made in america conversation has taken off elsewhere, too. so many americans going on twitter, and for the first time, a tally. since we started this journey, 946,565 tweets with those three words, made in america. "world news" viewers, a huge part of that. like samantha. just tweeted me, "did a little christmas shopping today for some friends, and the best part? all of it was #madeinamerica." and she sent me the picture to prove it. and who noticed this conversation? one of the founders of twitter. and we found him in new york, as he was shopping for made in america. he's seen the trend of twitter. and you've seen it? >> oh, yeah. >> reporter: jack dorsey. and without him, we wouldn't be sending those 140 character tweets. he says movements on twitter come in all sizes. >> some grow very, very large and global, an